Use a bitmask for SVG render object types

Source/core/rendering/RenderObject.h

Index: Source/core/rendering/RenderObject.h
diff --git a/Source/core/rendering/RenderObject.h b/Source/core/rendering/RenderObject.h
index 37044c4e86d4d75cf6aaf806978ec085e94876d0..c26d17233a4444338e227ca25f5ea9fafdf3a2eb 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -427,25 +427,48 @@ public:
     FlowThreadState flowThreadState() const { return m_bitfields.flowThreadState(); }
     void setFlowThreadState(FlowThreadState state) { m_bitfields.setFlowThreadState(state); }
 
-    // FIXME: Until all SVG renders can be subclasses of RenderSVGModelObject we have
-    // to add SVG renderer methods to RenderObject with an ASSERT_NOT_REACHED() default implementation.
-    virtual bool isSVGRoot() const { return false; }
-    virtual bool isSVGContainer() const { return false; }
-    virtual bool isSVGTransformableContainer() const { return false; }
-    virtual bool isSVGViewportContainer() const { return false; }
-    virtual bool isSVGGradientStop() const { return false; }
-    virtual bool isSVGHiddenContainer() const { return false; }
-    virtual bool isSVGPath() const { return false; }
-    virtual bool isSVGShape() const { return false; }
-    virtual bool isSVGText() const { return false; }
-    virtual bool isSVGTextPath() const { return false; }
-    virtual bool isSVGInline() const { return false; }
-    virtual bool isSVGInlineText() const { return false; }
-    virtual bool isSVGImage() const { return false; }
-    virtual bool isSVGForeignObject() const { return false; }
-    virtual bool isSVGResourceContainer() const { return false; }
-    virtual bool isSVGResourceFilter() const { return false; }
-    virtual bool isSVGResourceFilterPrimitive() const { return false; }
+    // FIXME: Until all SVG renderers are subclasses of RenderSVGModelObject, we have to
+    // maintain this parallel type system in RenderObject.
+    // Note: All updates to the SVG renderer hierarchy must update the enum below.
+    enum SVGType {
+        IsNotSVG = 0,
+        IsSVGRoot = 1,
+        IsSVGContainer = 1 << 1,
+        IsSVGTransformableContainer = 1 << 2 | IsSVGContainer,
+        IsSVGViewportContainer = 1 << 3 | IsSVGContainer,
+        IsSVGGradientStop = 1 << 4,
+        IsSVGHiddenContainer = 1 << 5 | IsSVGContainer,
+        IsSVGShape = 1 << 6,
+        IsSVGPath = 1 << 7 | IsSVGShape,
+        IsSVGText = 1 << 8,
+        IsSVGInline = 1 << 9,
+        IsSVGTextPath = 1 << 10 | IsSVGInline,
+        IsSVGInlineText = 1 << 11,
+        IsSVGImage = 1 << 12,
+        IsSVGForeignObject = 1 << 13,
+        IsSVGResourceContainer = 1 << 14 | IsSVGHiddenContainer,
+        IsSVGResourceFilter = 1 << 15 | IsSVGResourceContainer,
+        IsSVGResourceFilterPrimitive = 1 << 16 | IsSVGHiddenContainer
+    };
+    bool hasSVGType(SVGType mask) const { return mask == (mask & getSVGType()); }
+    bool isSVG() const { return getSVGType(); }
+    bool isSVGRoot() const { return hasSVGType(IsSVGRoot); }
+    bool isSVGContainer() const { return hasSVGType(IsSVGContainer); }
+    bool isSVGTransformableContainer() const { return hasSVGType(IsSVGTransformableContainer); }
+    bool isSVGViewportContainer() const { return hasSVGType(IsSVGViewportContainer); }
+    bool isSVGGradientStop() const { return hasSVGType(IsSVGGradientStop); }
+    bool isSVGHiddenContainer() const { return hasSVGType(IsSVGHiddenContainer); }
+    bool isSVGPath() const { return hasSVGType(IsSVGPath); }
+    bool isSVGShape() const { return hasSVGType(IsSVGShape); }
+    bool isSVGText() const { return hasSVGType(IsSVGText); }
+    bool isSVGTextPath() const { return hasSVGType(IsSVGTextPath); }
+    bool isSVGInline() const { return hasSVGType(IsSVGInline); }
+    bool isSVGInlineText() const { return hasSVGType(IsSVGInlineText); }
+    bool isSVGImage() const { return hasSVGType(IsSVGImage); }
+    bool isSVGForeignObject() const { return hasSVGType(IsSVGForeignObject); }
+    bool isSVGResourceContainer() const { return hasSVGType(IsSVGResourceContainer); }
+    bool isSVGResourceFilter() const { return hasSVGType(IsSVGResourceFilter); }
+    bool isSVGResourceFilterPrimitive() const { return hasSVGType(IsSVGResourceFilterPrimitive); }
 
     // FIXME: Those belong into a SVG specific base-class for all renderers (see above)
     // Unfortunately we don't have such a class yet, because it's not possible for all renderers
@@ -1056,6 +1079,8 @@ protected:
     // of this renderer within the current layer that should be used for each result.
     virtual void computeSelfHitTestRects(Vector<LayoutRect>&, const LayoutPoint& layerOffset) const { };
 
+    virtual SVGType getSVGType() const { return IsNotSVG; }
+
 private:
     RenderBlock* containerForFixedPosition(const RenderLayerModelObject* repaintContainer = 0, bool* repaintContainerSkipped = 0) const;